Flying Dutchman advice

I recently acquired a 1960’s Italian made Alpa Flying Dutchman. Unfortunately, the hull feels very questionable. It is extremely easy to push on it virtually anywhere and as a result, there is a lot of visible cracking. From what I have read, this hull is a non cored GRP layup which I guess is not known to be that strong or long lasting.
My question is, should I strengthen the existing hull by adding fiberglass to it? I’m not worried about the weight because I don’t plan on racing. At the very least I had planned on removing the deck and replacing it with wood and clear coating it.
At this point I want a FD one way or another so I either want to strengthen and reinforce THIS hull or build a new wood hull. Which do you think would be the best route? Thanks in advance for any help or advice!

Your initial thoughts are correct,the boat is an antique and they were never expected to last indefinitely.You will get more focused advice if pictures are available for perusal but a new member here may not be able to post them yet.You may need to adopt an attitude that is a flexible as your boat as the strength needs to be present in the critical areas and not uniformly applied,or the weight will increase massively.There are some areas where the hull does little more than preventing the inward passage of water and some where strength is absolutely essential,do you have the experience to determine which is which and as a supplementary question,do you have enough laminating experience to make a light layup satisfactory?The good news is that an FD has a large enough waterplane to withstand a bit of weight but that same weight won't be too welcome when you haul the boat up the ramp.

Building a new hull out of wood sounds extreme. As you aren't going racing, you can reinforce the heck out of the current one with no problems. Its way easier than building a new hull with the complex curves of these boats.
It would even be easier to use the current hull as a "Plug", build a Mould, and layup a new fibreglass hull than do one out of what would be strip planking.
A Plywood deck with a layer of glass and Epoxy is easy, as the decks are quite simple.

If you just add another layer or two of 'normal glass you may not add much stiffness, because 'glass itself is not very stiff and the extra layers will not be far off the neutral axis of the skin. You could consider perhaps epoxying on foam (or even lightweight timber) mini frames with some carbon tape on top of them in strategic spots?

Here's a brief thread on another Alpa resto;

Attempting to restore a 1959 Flying Dutchman built by ALPA https://forums.sailinganarchy.com/threads/attempting-to-restore-a-1959-flying-dutchman-built-by-alpa.155972/

For what it's worth perhaps you could just do a quick job on this FD and sail it while you keep an eye out for another FD. The Alpa could be a cheap way of getting spare parts to use on the new one.

I've sailed plenty of ancient and floppy Lasers. They don't appear to be significantly slower at club level and although they flex I've never seen a hull actually fail.

Fiberglass composites are very different today. I used to own a '68 fiberglass hull that was basically 1 layer of 24 ounce woven roving, and it felt about as structural as a warm Pop Tart. You get used to it. It was a MORC ocean racer and continued to cruise the Caribbean for many years after I owned it. You need to inspect the cracks around fittings and appendages. But at least you can get at both sides of the entire hull. It's biggest threat is letting it fill up with rainwater sitting on a trailer.

If you are going to work on the hull, I'd plan on working with the flex. There are specialty flex additives for almost all the paints, goops, and glops you need to refinish a hull.

I have a friend who fixed a floppy old single skin FD. The main area to focus on is the large flat bottom, as the curved bilge area is usually fine. He cut out all the (mostly debonded) stringers (these were just glass laid over cardboard tubes), cleaned off the gelcoat with a disc sander, laid core over the area (he used balsa, I'd use contour foam) and laminated glass over the whole lot, lapping it up into the bilge curve. All other spider cracks were dremelled out and filled, or gelcoat ground away and glass patches applied where there were actual cracks. Then all got hi build epoxy coated and 2 pack paint applied. You'd be around 1500 euros for all the materials.

Having seen that boat first hand I'm not sure I would have tried to work with allowing it to flex...it was a polyester resin build, and there were definite signs that it was ready to snap at the bulkhead under the mainsheet track. It's a long low hull on an FD, and unlike a floppy laser which is much smaller/lower loads and with an unstayed mast, the FD is a highly loaded beast at times.